BMR Calculator
Quickly find your Basal metabolic rate with our free BMR Calculator. Simple, fast, and accurate.
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Your BMR
What is a BMR Calculator?
A BMR Calculator estimates your Basal Metabolic Rate — the calories your body burns at complete rest. It is an essential starting point for understanding your total daily energy needs and planning your nutrition.
How to calculate BMR manually (the formula)
The Mifflin-St Jeor equation: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161. Results are in kcal per day.
Example calculation
A 30-year-old man weighing 72 kg at 175 cm: 10 × 72 + 6.25 × 175 − 5 × 30 + 5 = 720 + 1093.75 − 150 + 5 = 1669 kcal/day. His body burns about 1669 calories at rest.
Common mistakes
- Confusing BMR with RMR — RMR (Resting Metabolic Rate) is slightly higher than BMR because it includes digestion and light activity. BMR is measured under stricter conditions.
- Using incorrect equations — Older equations like Harris-Benedict can overestimate by 5–15%. The Mifflin-St Jeor equation is more accurate for the general population.
- Forgetting to update after weight change — BMR drops as you lose weight. Recalculate every 5–10 kg to keep your nutrition targets accurate.
Frequently asked questions
What is BMR?
BMR stands for Basal Metabolic Rate, the number of calories your body burns at rest to maintain basic functions like breathing and circulation.
How is BMR calculated?
The calculator uses the Mifflin-St Jeor equation. For men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161.
Why does BMR matter for weight loss?
BMR represents the majority of your total daily calorie burn. Knowing your BMR helps you set an appropriate calorie intake for weight loss or maintenance.
Does muscle mass affect BMR?
Yes, muscle tissue burns more calories at rest than fat tissue. People with higher muscle mass typically have a higher BMR.
Can BMR change over time?
Yes, BMR changes with age, weight loss, and changes in body composition. It generally decreases with age and after weight loss.